Paul played all the instruments on his first solo record. Everything on “Maybe, I’m Amazed” was him...not a shabby guitar solo there.
He did the guitar solo on “Taxman”, which was one of the better Beatle guitar solos.
And once John quipped that Ringo wasn’t even the best drummer in the Beatles.
John Lennon said a lot of things that he didn't necessarily believe just to stir the pot. All four of the Beatles were drummers and given their other talents, I don't doubt that they were all pretty good. Given that Keith Moon of the Who, Charlie Watts of the Rolling Stones and other notable drummers of the London rock scene considered Ringo as a kind of mentor, I'm inclined to respect their opinions on Ringo's abilities more than John Lennon's.